Abstract: A method of operating a computer system to convert non-interactive digital documents, such as electronic text and image files into interactive digital worksheets is provided. The method includes operating the computer system to prompt a user, such as a teacher for example, to identify a Base Document file accessible to the computer system. The computer system processes the Base Document to produce a corresponding dynamic document which allows the user to overlay data input fields overlaid. The user's overlays are recorded in a database along with meta-data that has been input by the user and which is associated with the overlaid data input fields. The meta-data that is recorded includes instructions determining the manner in which a further computational device, for example a student's PC, smartphone or tablet, interactively presents information of the base document to an end user, such as a student.